First two Ohio horses diagnosed with West Nile virus this season

REYNOLDSBURG, Ohio – Lab test results have confirmed the first two cases of the year of West Nile virus infection in Ohio horses.

This second straight year of West Nile virus infections in Ohio horses was anticipated by public and animal health officials.

Like most of the more than 600 equine cases reported by the Ohio Department of Agriculture for 2002, the two newly infected horses, one from Brown County and the other from Stark, had not been fully vaccinated. The two horses were euthanized after their health deteriorated.

“West Nile virus is in Ohio, and horse owners should know their animals are particularly susceptible to this dangerous disease,” said Fred L. Dailey, director of the Ohio Department of Agriculture.

“The best protection is to keep mosquitoes away from horses and to make sure horses are properly vaccinated, ideally before mosquito season starts.”

Vet reports. Veterinarian David Lippert of Lynchburg, Ohio, said a horse stabled in Brown County began showing signs of the viral infection July 28.

The symptoms eventually included fever, weakness in the front legs, and twitching of the shoulders.

The horse was euthanized on August 7. The animal had received no vaccination against the virus.

Veterinarian Francesca Sampieri of The Ohio State University said a horse stabled in Stark County began showing signs of infection July 31.

The symptoms eventually included drooping eyelids, facial twitching, and stumbling. The horse has since been euthanized.

The horse had received one vaccination in mid-July (two doses are recommended for an initial vaccination, followed by boosters in subsequent years).

Blood sampled. The department’s findings were based on blood samples from the horses taken by the veterinarians after the horses showed signs of infection and submitted to the department’s Animal Disease Diagnostic Laboratory for testing.

The department assists in the testing of horses and birds as part of the state’s efforts to monitor and prevent the spread of West Nile virus.

Horses are “sentinels” of the mosquito-borne disease rather than carriers – that is, horses can contract the disease but don’t transmit it to humans, birds, mosquitoes, or any other animal.

Horse owners should consult a veterinarian if telltale signs of infection are present in their animals, including loss of appetite; fever; muscle twitching, tremors, and weakness; paralysis of hind limbs; impaired vision; coordination loss and stumbling; circling and aimless wandering; convulsions; inability to swallow; hyper-excitability; coma; and death.

Vaccines. Dailey said owners should consult with their veterinarians to consider vaccinating horses against the virus.

A vaccine developed by Fort Dodge Laboratories, Inc., of Fort Dodge, Iowa, is approved by the Ohio Department of Agriculture for use in Ohio, as is a newer vaccine developed by Novartis Animal Vaccines, Inc., of Larchwood, Iowa, which is conditionally licensed by USDA.